1. Field of the Invention
The present invention relates to a laminated material for hot and cold cups and a manufacturing method therefor and, in particular, it relates to a laminated material for cups good for both hot and cold drinks and also having a good vending property, i.e. suited for sale by a vending machine, and a manufacturing method therefor.
2. Description of the Prior Art
Hitherto as cups for cold drinks such as carbonated drinks there have been widely adopted paper cups impregnated with a wax. Such a wax-impregnated paper cup is made by spraying a molded or formed cup with a molten mixture of paraffins (wax) by the use of a spray gun or the like to have it impregnated therewith for a sufficient water resistance and mechanical strength to be imparted to the paper. This wax-impregnated paper cup, however, had a number of problems or shortcomings, namely (1) the mixture of paraffins used for impregnation is approximately 55.degree..about.70.degree. C. in melting temperature, hence when it is used for a hot drink, there occurs undesirable melting out of paraffin/s, (2) when a soft-drink vending machine is placed where temperature is quite high, such cups therein tend to cause blocking due to softening of the wax used for impregnation, (3) the so-called vending properties such as stacking property are poor and (4) the manufacturing process is complicated and productivity is low.
Meanwhile, for hot drinks such as coffee paper cups coated with polyethylene have been often used, but they are usually matte-finished for improved stacking property, and when a cold drink such as a carbonated drink is poured into a cup of this kind, there results a phenomenon of sudden bubbling for the bubbles and the content to overflow, this type of cup being thus not suited for carbonated drinks or the like.
Such being the case, it has been necessary to provide two kinds of cups for hot and cold drinks respectively, this being markedly disadvantageous not only with respect to manufacturing facilities as well as process but also due to the required bulkiness of the vending machine, which means a substantial increase of its cost. The space required for installation of the machine is naturally increased, this resulting in a poor utilization efficiency of a given site and, worse, it is very troublesome to provide and take care of two kinds of cups.